CODEWITHSUNDEEP
c#autocadautocad-plugin
Jason Jackson
Jason Jackson

Reputation: 17260

Find unit of AutoCAD attribute in C#

I am grabbing all of the objects in the ModelSpace for an AutoCAD drawing. These objects are of various types like Pipe, Duct, DuctFitting, Line, Mesh, Solid3D, etc, so I am writing logic to determine their properties by reflecting with TypeDescriptor. I am wondering if there is a smarter way to go about getting all of the attributes of an object, and if there is a way to determine the units of measure for a given item. I know how to look up what units the drawing is using, but how can I tell that a property called "Length" is actually a length using the units from the drawing like feet or meters?

Here is the code I have to enumerate over all of the items I want:

using (var transaction = database.TransactionManager.StartTransaction())
{
    BlockTable blockTable = (BlockTable)transaction.GetObject(database.BlockTableId, OpenMode.ForRead);
    BlockTableRecord blockTableRecord = (BlockTableRecord)transaction.GetObject(blockTable[BlockTableRecord.ModelSpace], OpenMode.ForRead);

    foreach (DBObject dbObject in blockTableRecord
        .Cast<ObjectId>()
        .Where(id => id.IsValid && !id.IsNull && !id.IsEffectivelyErased && !id.IsErased)
        .Select(id => transaction.GetObject(id, OpenMode.ForRead))
    {
        //DISCOVER PROPERTIES AND THEIR UNITS HERE
    }
}

Upvotes: 1

Views: 2435

Answers (2)

kaps
kaps

Reputation: 186

This will help you.

UnitsValue unitValue=Application.DocumentManager.MdiActiveDocument.Database.Insunits;

UnitValue is enum which support 20 unit types including LightYear, Armstrong, etc...

Upvotes: 4

Mike Sandberg
Mike Sandberg

Reputation: 56

Reflection seems like a reasonable approach to me.

To find properties that have units associated with them you can check each property for Autodesk.AutoCAD.DatabaseServices.UnitTypeAttribute. For example, if you are using TypeDescriptor and are looking for properties that are distances it might look like this:

var distanceAttribute = new UnitTypeAttribute(UnitType.Distance);
foreach (PropertyDescriptor property in TypeDescriptor.GetProperties(dbObject))
{
    if (property.Attributes.Matches(distanceAttribute))
    {
        // Here's a property that is a distance.
    }
}

This relies on the API actually having UnitTypeAttribute applied where you would expect it.

Upvotes: 2

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